*University of Arhus, Denmark;
**Department of Agriculture, Western Australia

Summary

An experiment was carried out to evaluate effects of two
supplements (a formulated concentrate and cottonseed cake) for
cows kept in confinement by smallholders in villages in
Mauritius. The basal diet consisted mainly of sugar cane tops
(from July to December) and grasses harvested from roadsides and
common lands. The supplements were fed for 3 months prior to
calving and throughout lactation. The amounts of commercial feed
were 2, 3 kg/day for the 7th and 8-9th month of pregancy and 0.5
kg/litre of milk. The quantities of cottonseed cake were half the
amount of concentrate.

Lactation yields (litres) for concentrate and cottonseed cake
were 3023 and 2871 (wet area) and 2358 and 2649 (dry areas).
There were no differences in milk yield due to supplement but
yields were higher in cows kept in the wetter areas. Breed
effects (local "Creole", Friesian and crosses) were not
significant.

Key words: Milk production, cattle, sugar cane tops,
cottonseed cake.

Introduction

The annual production of fresh milk in Mauritius is
approximately 9 million litres which is equivalent to 12% of
total consumption of milk and milk products. In its continued
effort towards maximum self-sufficiency the Ministry has set a
target of 25% self sufficiency in terms of milk and meat by 1991.

In the villages of Mauritius milk production can be summarized
in the following way.

The village cattle breeders own about 11000 females over
one year of age. This represents about 65% of the female
national herd in this age group.

The cattle are a side-line activity of the family.

There are normally one to two cows per farm.

No forage is specifically cultivated for the cows. Forage
sources include sugar cane tops, and shrubs and grasses
which are found on road-sides and on common land.

The housing and shelter of the tethered animals is often
rudimentary.

Milk is sold to neighbours or to small scale (20 - 25
l/d) milk sellers who then distribute the milk.

There is little or no use of concentrate feeds as
supplements to the hand-collected forage.

The cattle are a mixture of the local Creole breed and
Friesians. Artificial insemination is subsidised by the
Governement and is widely used.

On the basis that the small breeders make a major contribution
to national production of fresh milk the work reported here was
designed to investigate the extent to which productivity in this
sector could be improved.

As far back as 1956, Bennie reported that the local Creole
cattle could double their milk production with improved feeding.
In 1971 an FAO project on Milk and Meat Production suggested that
the most important factor limiting milk production was the supply
of a protein concentrate to the cow. This FAO project also
demonstrated that milk yield could be increased considerably by
better feeding and management.

More recently Dolberg and Rowe (1984), in reviewing
experimental work done by the Mauritian Ministry of Agriculture
on milk production, concluded that under local conditions
greatest responses in milk production would be expected from
protein supplementation. They referred to the work of Mapoon
et al (1977) which showed that ground nut cake was more
efficient then either a balanced concentrate feed, or a
molasses/urea mixture, as a supplement for milk production; and
to that of Gaya et al (1982) who reported that
supplementation with cottonseed cake increased milk production
more effectively than the formulated concentrate
"cowfeed". In fact, similar increases in milk
production were achieved with about half the level of cotton seed
cake as commercial concentrate. A second advantage of cottonseed
cake as a supplementary feed is that it requires no mixing.

The project described here was designed to investigate and
compare the effect of two types of supplements: the commercial
concentrate "cowfeed" and the protein-rich cotton seed
cake. In addition to the measurements of milk production the
study provided the oportunity to investigate the nutritive value
of the most commonly used feed resources (see Boodoo et al
1990).

Methods

Location and treatments

The study was carried out in two locations:

Cottage and l'Esperance Trebuchet in the drier northern
part of the island (Mapou area) (1450 mm rain yearly).

In each area 22 cows received each of the two supplements
(cotton seed cake or cowfeed) during the 3-months precalving and
the following 10-months of lactation.

Supplementary feeds and feeding

"Cowfeed" is a locally compounded concentrate feed
for dairy cows, with about 17% crude protein on fresh matter
basis. The formulation of is as follows: wheat bran 5%, rice bran
11.5%, maize 20%, cottonseed cake (or groundnut cake) 30%,
molasses 30%, common salt 1% and calcium carbonate 2.5%. Only
approximately 45% (by weight) of these ingredients is produced
locally - half of the maize and all of the molasses, salt and
lime. The cottonseed cake was purchased either from Zimbabwe or
India and was fed together with a mineral supplement of 15 g
sodium chloride and 50 g calcium carbonate per day.

The amounts and the pattern of feeding the supplements are
summarized in Table 1. During lactation the amount of concentrate
fed was adjusted each week according to the previous week's milk
production and the predicted production for the following week.

Table 1: Daily
levels of supplementation during the last 3 months of
pregnancy and during lactation.

Cowfeed

Cotton seed
cake

Pregnancy
(kg/head)

7th month

2

1

8th and 9th
month

3

1

Lactation
(kg/litre milk)

0.5

0.25

Selection of cows and allocation to
treatments

A group of participating farmers was identified by first
explaining the objectives and benefits of the project to milk
producers in the two areas. For those participating, the
supplements were provided free of charge through the UNDP project
(MAR 82/007) and on this basis farmers voluntarily registered
their names.

Cows that were 7-months pregnant were accepted to participate
in the project and these were allocated alternately to each of
the two treatments - cowfeed and cotton seed cake. A total of 44
cows was selected in each climatic area.

Breeds

The animals were representative of the following breeds:
Creole, Friesian and Friesian-Creole crosses at various levels of
crossbreeding. The Creole cow, which is the local breed, is of
the Bostaurus type. It is of medium size (in the
range 300 - 400 kg adult liveweight), polled and humpless. It is
predominantly white or white brown with dun, black or brown
characteristic spots.

Milking and milk recording

The cows were hand-milked twice a day, in the early morning at
about 5.30 a.m. and in the afternoon at about 6 p.m. Milk
production was recorded daily by extension officers in each area
travelling on a bicycle. These field officers visited the
cowkeepers at dawn and dusk, to measure the amount of milk
produced. A volumetric measure called a "quart" (5
quarts to a litre) is traditionally used in Mauritius. A record
book was kept permanently at the cowkeeper's place for the
recording. In addition, a weekly record sheet was used to
transfer the milk records to the master file. All calves were
bucket-fed during the experiment. This was a pre-requisite for
participation in the project in order to obtain a precise
measurement of milk production.

Forage and forage consumption

The cowkeeper was responsible for the collection of fodder
according to normal practices. During the crop season (June to
mid December) the main source of forage is canetops. In the
intercrop season a variety of grasses, shrubs, twigs, creepers
and vegetable crop residues are usually collected from the road
verges, common land and adjacent fields. The forages were fed to
appetite at all times. The amounts of fodder offered and consumed
were recorded. In addition, samples of forages were taken weekly
for chemical analysis and nylon bag degradability. These data are
reported in a separate paper (Boodoo et al 1990).

Chemical analysis and nylon bag
digestibility

Samples of the supplements were taken at intervals of
approximately 14 days and sent to the Agricultural Chemistry
Laboratory, Reduit, for analysis (dry matter, crude protein,
crude fibre, ether extract and ash.)

Results

Milk production and composition

Effect of supplement and area

The mean milk production of cows in the two areas on the two
types of supplement is summarised in Table 2. There was
considerable variation in the age and lactation number in the
cows. However, there were no significant differences in these
parameters between treatment groups and milk production data have
been averaged for all animals. In the same way, milk production
data have been calculated for all breeds together.

Table 2:
Mean milk production and composition during the full 301
day lactation according to area and type of supplement

Vacoas

Mapou

Cowfeed

CSC

Cowfeed

CSC

Milk
production (kg)

301d
lactation

3023

2871

2538

2649

SE

146

104

139

129

Milk
composition (%)

Fat

4.08

4.57

4.31

4.61

SE

0.222

0.164

0.183

0.192

Protein

3.41

3.58

3.47

3.40

SE

0.149

0.118

0.061

0.089

When averaged over the whole trial the concentration of milk
fat was not significantly higher in the animals fed cottonseed
cake and there was little effect of area or supplement on protein
concentration.

The effect of breed

All animals were classified on the basis of their phenotypic
appearance into one of three categories: (i) Friesian; (ii)
Friesian x Creole; and (iii) Creole. The milk production of the
animals in these three categories is summarised in Table 3 for
the two areas.

Seasonal effects on milk production

There were differences between the two regions in the pattern
of milk production with time. Fig 4 summarises the mean daily
milk production for each month of the year in the Vacoas and
Mapou areas. It is clear that from the start of May until the end
of August there was little difference between the pattern of milk
production in the two regions. The milk production in the Vacoas
area remained high from August to January and fell from February
to May. On the other hand the milk production on the Mapou area
reached a peak around August and from then until May was
significantly lower than that measured in the Vacoas area.

Table 3:
Milk production by breed type in the Vacoas and Mapou
areas. Data are summarised for the total milk production
over the 301 d lactation and for the "peak daily
production" for the second month of lactation.

Creole

Cross-bred

Fresian

Vacoas area

Total
(litres)

2788

2958

2899

SE

232

115

176

"Peak"
(litres/d)

13.0

14.5

13.8

SE

0.2

0.5

0.8

Mapou area

Total

2889

2536

2459

SE

216

124

156

"Peak"

12.1

12.4

10.3

SE

0.4

0.6

0.7

There were no significant differences in total
or "peak" milk production due to breed.

The average milk production of cows calving during the crop
season (June to November) was 2950 kg and was significantly (P
<0.001) higher than the average for cows calving outside the
cropping season (December to May) which was 2639 kg.

Table 4: Effect
of season (month) on mean daily milk yield (litres) of
cows in the wet (Vacoas) and dry (Mapou) area

Month

Vacoas

Mapou

SEdif

Month

Vacoas

Mapou

SEdif

Jan

10.4

7.7

0.8

Jul

9.7

9.3

1

Feb

9.6

7.7

1

Aug

10.7

10.6

1

Mar

9

7.8

1.1

Sep

11

10.2

1

Apr

8.3

8.5

0.8

Oct

11.3

9.5

1

May

8.5

8.2

1.2

Nov

10.3

8.5

0.9

Jun

9

9

0.8

Dec

10.5

7.8

0.8

Analysis of feed

Supplements

The results of the chemical analyses carried out on the
supplements are shown in Table 5. The crude protein content of
the cottonseed cake (41.1%) is slightly more than twice that of
the cowfeed (17.4%).

Table 5: Chemical
composition (% air dry) of the concentrate and cottonseed
cake

DM

CP

Ash

EE

CF

Ca

P

Cowfeed

84.2

17.4

10.2

1.13

5.8

1.10

0.4

SE

0.5

0.2

0.2

0.2

0.1

0.06

0.056

N

47

48

48

21

21

12

12

CSC

90.5

41.1

6.3

5.9

11.3

0.17

1.1

SE

0.3

0.4

0.1

1.2

0.6

0.01

0.11

N

37

38

38

15

15

12

12

Forages

The quality and the amounts of fresh forage consumed during
the lactation period are described in a separate paper (Boodoo et
al 1990).

Discussion

The findings in this village-based trial, that cottonseed cake
was more efficient (250 g/litre of milk) than a
"balanced" concentrate (500 g/litre) as a supplement
for basal diets of moderate digestibility (about 55%
degradability in situ) and low nitrogen content (1-2% N in DM),
confirm the earlier reports by Mapoon et al (1977) and Gaya et al
(1982) carried out under experiment station conditions. They
provide strong support for the hypothesis that "bypass"
nutrients, especially protein are the principal limitations to
ruminant production on tropical forages (Preston and Leng 1987).

The quantity of milk produced by the village cows in this
experiment (9.2 kg/d during 300 days) is higher than the average
production of between 3.5 and 9.2 kg/d reported for the
Government stations where cowfeed is fed at the rate of 0.5 kg/kg
milk. It is also relevant to compare it with the milk production
of unsupplemented village cows (4 to 5 kg/d for a lactation
period of around 225 days).

Although there were only 23 (about 25%) Creole cows in the
study their milk production potential appeared to be equal to the
more exotic genotypes with a daily mean of 9.6 and 8.3 kg per
head for a 301- day lactation in the Vacoas and Mapou areas
respectively. This indicates that under these village conditions
the Creole breed has a similar performance to the imported
Friesians or their crosses.

Acknowledgements

Acknowledgement is made to the UNDP for funds made available
through Project MAR 82/007; the Extension Division, the Chemistry
Division and the Division of Veterinary Services of the Ministry
of Agriculture, Fisheries and Natural Resources for their
collaboration. Statistical help was provided by the Agronomy
Division. We are also grateful to the cowkeepers who agreed to
participate in the project.

MaPoon L K, Delaitre J C and Preston T R
1977 The value for milk production of supplements of mixtures
of final molasses, bagasse pith and urea, with and without
combinations of maize and groundnut cake. Tropical Animal
Production 2:148-150.

Preston T R and Leng R A 1987 Matching
Ruminant Production Systems with Available Resources in the
Tropics and Subtropics. PENAMBUL Books Ltd: Armidale NSW,
Australia